Field of the Invention
The present invention relates to a drawing control technique of a printer driver.
Description of the Related Art
Printing systems from Microsoft Corporation have used a graphics engine called the graphics device interface (GDI). A printing flow using the GDI has been as follows:
(1) In accordance with a print instruction from a user, a GDI application calls a GDI service function group and issues GDI drawing commands;
(2) The issued GDI drawing commands are spooled in a data format called the enhanced metafile (EMF), and passed to a printer driver for GDI (hereinafter referred to as “GDI driver”); and
(3) The GDI driver converts drawing data formed by the GDI drawing commands (hereinafter referred to as “GDI drawing data”) to print data (so-called page description language (PDL) data) interpretable by a printing apparatus, and outputs the print data to the printing apparatus.
Such a processing flow that involves printing from the GDI application via the GDI driver will hereinafter be referred to as a “GDI print path”. Recently, a new printing flow called an “XPS print path.” has been added to the GDI print path. The XPS is an extensible markup language (XML)-based electronic document format and an abbreviation for the XML paper specification. In the XPS print path, an application that supports XPS (i.e., XPS application) generates XPS drawing data, which is converted to print data by a printer driver for XPS (hereinafter referred to as “XPS driver”) and output to the printing apparatus.
The GDI print path and the XPS print path are not exclusive to each other. For example, GDI drawing data generated by the GDI application using GDI can be converted to XPS drawing data, which can then be converted to print data by the XPS driver. In the case of printing from the GDI application using the XPS driver, conversion from GDI drawing data to XPS drawing data is done by a conversion module called the Microsoft XPS document writer (MXDW).
Print settings in the GDI driver include a “pattern resolution setting” for specifying the resolution of a pattern drawing in printing of a document file including the pattern drawing. The pattern drawing refers to a drawing created by filling a figure with one of various repeating drawing units called patterns. FIG. 1 illustrates various patterns used in a pattern drawing. After selecting a pattern, the user specifies a resolution, such as 300 dpi or 600 dpi, as the “pattern resolution setting”, so that the selected pattern can be drawn with desired fineness (e.g., at the specified resolution). The “pattern resolution setting” is also used for the purpose of avoiding unevenness caused by interference between a pattern and a halftone screen used in printing. Japanese Patent Laid-Open No. 2000-222152 discloses a technique in which, in creating a pattern drawing, the occurrence of moiré is avoided by enlarging or reducing a pattern in consideration of interference between the pattern and a halftone screen.
However, print settings of the XPS driver do not include the “pattern resolution setting” described above. When GDI drawing data from the GDI application is printed by the XPS driver, the MXDW converts the GDI drawing data to XPS drawing data always at a fixed resolution of a pattern drawing, such as 150 dpi. In this case, if a document file created by the GDI application includes a pattern drawing, the pattern roughness in the pattern drawing varies depending on whether printing is performed via the GDI driver or the XPS driver.